Yamaguchi Yusuke, Tabata Keiichi, Asami Satoru, Miyake Muneharu, Suzuki Takashi
Clinical Pharmacy, College of Pharmacy, Nihon University, Japan.
Biol Pharm Bull. 2007 Apr;30(4):638-43. doi: 10.1248/bpb.30.638.
Neuroblastoma (NB) often causes spontaneously regression, and can mature to ganglioneuroma. The form with the most favorable prognosis expresses high levels of TrkA, a high-affinity receptor for nerve growth factor (NGF), whereas advanced NB and associated cell lines have abnormalities in the NGF/TrkA signaling pathway. A novel cyclophane, cyclophane pyridine (CPPy), was designed to conserve the tyrosine phosphorylation of TrkA, thereby enhancing NGF/TrkA signal transduction. We investigated whether this compound improved NGF-induced tyrosine phosphorylation of the Y490 domain of TrkA and conserved the expression of an early gene (c-fos) in human NB cell lines (IMR-32 and NB-39). As determined by Western blotting, TrkA (Y490) phosphorylation was enhanced by the combination of CPPy (10(-8) M) and NGF (100 ng/ml) compared with NGF alone. CPPy also conserved NGF-induced c-fos mRNA expression. Moreover, CPPy induced the morphological differentiation of NB cells, leading to expression of the neuronal marker gene GAP-43. These data suggest that CPPy can induce the differentiation of NB cell lines by facilitating NGF-induced TrkA/Ras/MAPK signal transduction, and may therefore be an effective therapeutic agent for NB.
神经母细胞瘤（NB）常可自发消退，并可成熟为神经节神经瘤。预后最良好的类型表达高水平的TrkA，即神经生长因子（NGF）的高亲和力受体，而晚期NB及相关细胞系在NGF/TrkA信号通路存在异常。一种新型环番，即环番吡啶（CPPy），被设计用于维持TrkA的酪氨酸磷酸化，从而增强NGF/TrkA信号转导。我们研究了该化合物是否能改善NGF诱导的人NB细胞系（IMR-32和NB-39）中TrkA的Y490结构域的酪氨酸磷酸化，并维持早期基因（c-fos）的表达。通过蛋白质印迹法测定，与单独使用NGF相比，CPPy（10⁻⁸ M）与NGF（100 ng/ml）联合使用可增强TrkA（Y490）的磷酸化。CPPy还能维持NGF诱导的c-fos mRNA表达。此外，CPPy可诱导NB细胞的形态分化，导致神经元标记基因GAP-43的表达。这些数据表明，CPPy可通过促进NGF诱导的TrkA/Ras/MAPK信号转导来诱导NB细胞系分化，因此可能是一种有效的NB治疗药物。
